Order this document by MC145422/D SEMICONDUCTOR TECHNICAL DATA The MC145422 and MC145426 UDLTs are high–speed data transceivers that provide 80 kbps full–duplex data communication over 26 AWG and larger twisted–pair cable up to two kilometers in distance. Intended primarily for use in digital subscriber voice/data telephone systems, these devices can also be used in remote data acquisition and control systems. These devices utilize a 256 kilobaud modified differential phase shift keying burst modulation technique for transmission to minimize RFI/ EMI and crosstalk. Simultaneous power distribution and duplex data communication can be obtained using a single twisted–pair wire. These devices are designed for compatibility with existing, as well as evolving, telephone switching hardware and software architectures. The UDLT chip–set consists of the MC145422 Master UDLT for use at the telephone switch linecard and the MC145426 Slave UDLT for use at the remote digital telset and/or data terminal. The devices employ CMOS technology in order to take advantage of their reliable low–power operation and proven capability for complex analog/digital LSI functions. P SUFFIX PLASTIC DIP CASE 708 22 1 DW SUFFIX SOG PACKAGE CASE 751E 24 1 ORDERING INFORMATION MC145422P MC145426P Plastic DIP Plastic DIP MC145422DW SOG Package MC145426DW SOG Package • Provides Full–Duplex Synchronous 64 kpbs Voice/Data Channel and Two 8 kbps Signaling Data Channels Over One 26 AWG Wire Pair Up to Two Kilometers • Compatible with Existing and Evolving Telephone Switch Architectures and Call Signaling Schemes • Automatic Detection Threshold Adjustment for Optimum Performance Over Varying Signal Attenuations • Protocol Independent • Single 5 V Power Supply • 22–Pin PDIP, 24–Pin SOG Packages • Application Notes AN943, AN949, AN968, AN946, and AN948 MC145422 Master UDLT • Pin Controlled Power–Down and Loopback Features • Signaling and Control I/O Capable of Sharing Common Bus Wiring with Other UDLTs • Variable Data Clock — 64 kHz to 2.56 MHz • Pin Controlled Insertion/Extraction of 8 kbps Channel into LSB of 64 kbps Channel for Simultaneous Routing of Voice and Data Through PCM Voice Path of Telephone Switch MC145426 Slave UDLT • Compatible with MC145500 Series PCM Codec–Filters • Pin Controlled Loopback Feature • Automatic Power–Up/Power–Down Feature • On–Chip Data Clock Recovery and Generation • Pin Controlled 500 Hz D3 or CCITT Format PCM Tone Generator for Audible Feedback Applications REV 2 9/95 Motorola, Inc. 1995 MOTOROLA MC145422•MC145426 1 PIN ASSIGNMENTS MC145422 — MASTER (PLASTIC PACKAGE) MC145422 — MASTER (SOG PACKAGE) VSS 1 22 VDD VSS 1 24 VDD Vref 2 21 LO1 Vref 2 23 LO1 LI 3 20 LO2 LI 3 22 LO2 LB 4 19 RE1 NC 4 21 NC VD 5 18 Rx LB 5 20 RE1 SI1 6 17 TDC/RDC VD 6 19 Rx 7 18 TDC/RDC SO1 7 16 CCI SI1 SI2 8 15 Tx SO1 8 17 CCI SO2 9 14 TE1 SI2 9 16 Tx SE 10 13 SIE SO2 10 15 TE1 PD 11 12 MSI SE 11 14 SIE PD 12 13 MSI MC145426 — SLAVE (PLASTIC PACKAGE) MC145426 — SLAVE (SOG PACKAGE) VSS 1 22 VDD VSS 1 24 VDD Vref 2 21 LO1 Vref 2 23 LO1 LI 3 20 LO2 LI 3 22 LO2 LB 4 19 RE1 NC 4 21 NC VD 5 18 Rx LB 5 20 RE1 SI1 6 17 CLK VD 6 19 Rx SO1 7 16 X2 SI1 7 18 CLK SI2 8 15 X1 SO1 8 17 X2 SO2 9 14 Tx SI2 9 16 X1 Mu/A 10 13 TE1 SO2 10 15 Tx PD 11 12 TE Mu/A 11 14 TE1 PD 12 13 TE MC145422•MC145426 2 NC = NO CONNECTION MOTOROLA MC145422 MASTER UDLT BLOCK DIAGRAM +1 LO2 –1 MODULATION MODULATOR LO1 BUFFER SI1 * SI2 SE RE1 RECEIVE Rx REGISTER LB * SEQUENCE AND CONTROL DIVIDE CCI MSI PD * SIE * DEMODULATOR VD CONTROL LI VD SO1 DEMODULATION BUFFER * SO2 Tx TE1 TDC/RDC TRANSMIT REGISTER * — SE controlled latch MC145426 SLAVE UDLT BLOCK DIAGRAM +1 LO2 –1 MODULATION MODULATOR LO1 BUFFER LOOPBACK CONTROL RECEIVE SI1 SI2 Rx RE1 TONE GEN. REGISTER Mu/A LB TE PD X2 POWER– DOWN CONTROL SEQUENCE AND CONTROL CLK VD CONTROL VD OSC LI MOTOROLA DEMODULATOR X1 DEMODULATION BUFFER * SO1 SO2 TRANSMIT Tx REGISTER TE1 MC145422•MC145426 3 ABSOLUTE MAXIMUM RATINGS (Voltage Referenced to VSS) Symbol Rating DC Supply Voltage Value Unit VDD – VSS – 0.5 to + 9.0 V Voltage, Any Pin to VSS V – 0.5 to VDD + 0.5 V DC Current, Any Pin (Excluding VDD, VSS) I ± 10 mA TA – 40 to + 85 °C Tstg – 85 to + 150 °C Operating Temperature Storage Temperature This device contains circuitry to protect the inputs against damage due to high static voltages or electric fields; however, it is advised that normal precautions be taken to avoid applications of any voltage higher than maximum rated voltages to this high impedance circuit. For proper operation it is recommended that Vin and Vout be constrained to the range V SS ≤ (Vin or Vout) ≤ VDD. Reliability of operation is enhanced if unused inputs are tied to an appropriate logic voltage level (e.g., either VSS or VDD). RECOMMENDED OPERATING CONDITIONS (TA = 0 to 70°C) Pins Min Max DC Supply Voltage VDD 4.5 5.5 V Power Dissipation (PD = VDD, VDD = 5 V) VDD — 80 mW Power Dissipation (PD = VSS, TE = VSS) VDD — 75 mW MC145422 Frame Rate MSI 7.9 8.1 kHz — — 0.25 % Parameter MC145422 — MC145426 Frame Rate Slip (See Note 1) CCI Clock Frequency (MSI = 8 kHz) Unit CCI — 2.048 MHz Data Clock Rate MC145422 TDC, RDC 64 2560 kHz Modulation Baud Rate (See Note 2) LO1, LO2 — 256 kHz NOTES: 1. The MC145426 crystal frequency divided by 512 must equal the MC145422 MSI Frequency ± 0.25% for optimum operation. 2. Assumes crystal frequency of 4.096 MHz for the MC145426 and 2.048 MHz CCI for the MC145422. DIGITAL CHARACTERISTICS (VDD = 5 V, TA = 0 to 70°C) Parameter Input High Level Input Low Level Input Current Except LI LI Input Capacitance Min Max Unit 3.5 — V — 1.5 V – 1.0 – 100 1.0 100 µA — 7.5 pF Output High Current (Except Tx on MC145422 and Tx and PD on MC145426) VOH = 2.5 V VOH = 4.6 V – 1.7 – 0.36 — — mA Output Low Current (Except Tx on MC145422 and Tx and PD on MC145426) VOL = 0.4 V VOL = 0.8 V 0.36 0.8 — — mA PD Output High Current (MC145426) (See Note 1) VOH = 2.5 V VOH = 4.6 V – 90 – 10 — — µA PD Output Low Current (MC145426) (See Note 1) VOL = 0.4 V VOL = 0.8 V 60 100 — — µA Tx Output High Current VOH = 2.5 V VOH = 4.6 V – 3.4 – 0.7 — — mA Tx Output Low Current VOL = 0.4 V VOL = 0.8 V 1.7 3.5 — — mA Tx Input Impedance (TE1 = VSS, MC145422) 100 — kΩ Crystal Frequency (MC145426, Note 2) 4.0 4.4 MHz PCM Tone (TE = VDD, MC145426) – 22 – 18 dBm0 Three–State Current (SO1, SO2, VD, Tx on MC145422, Tx on MC145426) — ±1 µA Vref Voltage (See Note 3) 2 3 V X2 — Oscillator Output High Drive Current (MC145426) (See Note 4) VOH = 4.6 V – 450 — µA X2 — Oscillator Output Low Drive Current (MC145426) (See Note 4) VOL = 0.4 V 450 — µA NOTES: 1. To overdrive PD from a low level to 3.5 V or a high level to 1.5 V requires a minimum of ± 800 µA drive capability. 2. The MC145426 crystal frequency divided by 512 must equal the MC145422 MSI frequency ± 0.25% for optimum performance. 3. Vref typically (9/20 VDD – VSS). 4. Output drive when X1 is being driven from an external clock. MC145422•MC145426 4 MOTOROLA ANALOG CHARACTERISTICS (VDD = 5 V, TA = 0 to 70°C) Parameter Modulation Differential Amplitude (RL = 440 Ω) LO1 to LO2 Modulation Differential DC Offset Demodulator Input Amplitude (See Note) Demodulator Input lmpedance Min Max Unit 4.5 6.0 V p–p 0 300 mV 0.050 2.5 V peak 50 150 kΩ NOTE: The input level into the demodulator to reliably demodulate incoming bursts. Input referenced to Vref. MC145422 SWITCHING CHARACTERISTICS (VDD = 5 V, TA = 25°C, CL = 50 pF) Parameter Figure No. Symbol Min Max Unit Input Rise Time All Digital Inputs 1 tr — 4 µs Input Fall Time All Digital Inputs 1 tf — 4 µs TDC/RDC, RE1, MSI 1 tw(H,L) 90 — ns 1 tw(H,L) 45 55 % TDC/RDC — tDC 64 2560 kHz MSI to SO1, SO2 VD (PD = VDD) TDC to Tx 2 3 tPLH, tPHL — — 90 90 ns MSI to TDC/RDC Setup Time 4 tsu3 tsu4 90 40 — — ns TE1/RE1 to TDC/RDC Setup Time 4 tsu3 tsu4 90 40 — — ns Rx to TDC/RDC Setup Time 5 tsu5 60 — ns Rx to TDC/RDC Hold Time 5 th1 60 — ns SI1, SI2 to MSI Setup Time 6 tsu6 60 — ns SI1, SI2 to MSI Hold Time 6 th2 60 — ns Pulse Width CCI Duty Cycle Data Clock Frequency Propagation Delay Time MC145426 SWITCHING CHARACTERISTICS (VDD = 5 V, TA = 25°C, CL = 50 pF) Parameter Figure No. Symbol Min Max Unit Input Rise Time All Digital Inputs 1 tr — 4 µs Input Fall Time All Digital Inputs 1 tf — 4 µs CLK 1 tw(H,L) 3.8 4.0 µs — fX1 4.086 4.1 MHz 7 7 7 8 8 8 9 9 tp1 tp1 tp2 tp3 tp4 tp4 tp5 tp6 – 50 438 — — – 50 438 — — 50 538 40 40 50 538 90 90 ns Rx to CLK Setup Time 5 tsu5 60 — ns Rx to CLK Hold Time 5 th1 60 — ns SI1, SI2 to TE1 Setup Time 6 tsu6 60 — ns SI1, SI2 to TE1 Hold Time 6 th2 60 — ns Clock Output Pulse Width Crystal Frequency Propagation Delay Times MOTOROLA TE1 Rising to CLK (TE = VDD) TE1 Rising to CLK (TE = VSS) CLK to TE1 Falling CLK to RE1 Rising RE1 Falling to CLK (TE = VDD) RE1 Falling to CLK (TE = VSS) CLK to Tx TE1 to SO1, SO2 MC145422•MC145426 5 SWITCHING WAVEFORMS tw(H) tw(L) 90% 50% CLK, TDC, RDC, RE1, CCI, MSI 50% 10% tr tf Figure 1. 70% 70% MSI tPLH tPHL 70% VD, SO1, SO2 30% Figure 2. 70% 70% TDC tPLH tPHL 70% Tx 30% Figure 3. MC145422•MC145426 6 MOTOROLA SWITCHING WAVEFORMS (continued) 70% TE1, RE1, MSI 30% tsu3 tsu4 70% TDC, RDC 30% Figure 4. 70% TDC, RDC, CLK 30% tsu5 th1 70% 70% 30% 30% Rx Figure 5. tsu6 70% TE1 (MC145426) OR MSI (MC145422) 30% th2 70% 70% 30% 30% SI1, SI2 Figure 6. MOTOROLA MC145422•MC145426 7 SWITCHING WAVEFORMS (continued) 70% TE1 30% tP2 tP1 70% 70% CLK Figure 7. 70% RE1 30% tP3 tP4 70% 70% CLK Figure 8. 70% 70% Tx SO1, SO2 30% 30% tP6 tP5 70% 70% CLK TE1 Figure 9. MC145422•MC145426 8 MOTOROLA MC145422 MASTER UDLT PIN DESCRIPTIONS VDD Positive Supply Normally 5 V. VSS Negative Supply This pin is the most negative supply pin, normally 0 V. Vref Reference Output This pin is the output of the internal reference supply and should be bypassed to VDD and VSS by 0.1 µF capacitors. No external dc load should be placed on this pin. LI Line Input This input to the demodulator circuit has an internal 100 kΩ resistor tied to the internal reference node so that an external capacitor and/or line transformer may be used to couple the input signal to the part with no dc offset. LB Loopback Control A low on this pin disconnects the LI pin from internal circuitry, drives LO1, LO2 to Vref and internally ties the modulator output to the demodulator input which loops the part on itself for testing in the system. The state of this pin is internally latched if the SE pin is brought and held low. Loopback is active only when PD Is high. VD Valid Data Output A high on this pin indicates that a valid line transmission has been demodulated. A valid transmission is determined by proper sync and the absence of detected bit errors. VD changes state on the leading edge of MSI when PD is high. When PD is low, VD changes state at the end of demodulation of a line transmission. VD is a standard B–series CMOS output and is high impedance when SE is held low. SI1, SI2 Signaling Bit Inputs Data on these pins is loaded on the rising edge of MSI for transmission to the slave. The state of these pins is internally latched if SE is held low. SO1, SO2 Signaling Bit Outputs These outputs are received signaling bits from the slave UDLT and change state on the rising edge of MSI if PD is high, or at the completion of demodulation if PD is low. These outputs have standard B–series CMOS drive capability and are high impedance if the SE pin is held low. SE Signal Enable Input If held high, the PD, LB, SI1, SI2, and SIE inputs and the SO1, SO2, and VD outputs function normally. If held low, the state of these inputs is latched and held internally while the outputs are high impedance. This allows these pins to be bussed with those of other UDLTs to a common controller. MOTOROLA PD Power–Down Input If held low, the UDLT ceases modulation. In power–down, the only active circuit is that which is necessary to demodulate an incoming burst and output the signal and valid data bits. Internal data transfers to the transmit and receive registers cease. When brought high, the UDLT powers up, and waits three positive MSI edges or until the end of an incoming transmission from the slave UDLT and begins transmitting every MSI period to the slave UDLT on the next rising edge of the MSI. MSI Master Sync Input This pin is the system sync and initiates the modulation on the twisted pair. MSI should be approximately leading–edge aligned with TDC/RDC. SIE Signal Insert Enable This pin, when held high, inserts signal bit 2 received from the slave into the LSB of the outgoing PCM word at Tx and will ignore the SI2 pin and use in place the LSB of the incoming PCM word at Rx for transmission to the slave. The PCM word to the slave will have LSB forced low in this mode. In this manner, signal bit 2 to/from the slave UDLT is inserted in to the PCM words the master sends and receives from the backplane for routing through the PABX for simultaneous voice/data communication. The state of this pin is internally latched if the SE pin is brought and held low. TE1 Transmit Data Enable 1 Input This pin controls the outputting of data on the Tx pin. While TE1 is high, the Tx data is presented on the eight rising edges of TDC/RDC. TE1 is also a high–impedance control of the Tx pin. If MSI occurs during this period, new data will be transferred to the Tx output register in the ninth high period of TDC/RDC after TE1 rises; otherwise, it will transfer on the rising edge of MSI. TE1 and TDC/RDC should be approximately leading–edge aligned. Tx Transmit Data Output This three–state output presents new voice data during the high periods of TDC/RDC when TE1 is high (see TE1). CCI Convert Clock Input A 2.048 MHz clock signal should be applied to this pin. The signal is used for internal sequencing and control. This signal should be coherent with MSI for optimum performance but may be asynchronous if slightly worse error rate performance can be tolerated. TDC/RDC Transmit/Receive Data Clock This pin is the transmit and receive data clock and can be 64 kHz to 2.56 MHz. Data is output at the Tx pin while TE1 is high on the eight rising edges of TDC/RDC after the rising edge of TE1. Data on the Rx pin is loaded into the receive register of the UDLT on the eight falling edges of TDC/RDC after a positive transition on RE1. This clock should be approximately leading–edge aligned with MSI. MC145422•MC145426 9 Rx Receive Data SI1, SI2 Signaling Bit Inputs Voice data is clocked into the UDLT from this pin on the falling edges of TDC/RDC under the control of RE1. Data on these pins is loaded on the rising edge of TE1 for transmission to the master. If no transmissions from the master are being received and PD is high, data on these pins will be loaded into the part on an internal signal. Therefore, data on these pins should be steady until synchronous communication with the master has been established, as indicated by the high on VD. RE1 Receive Data Enable 1 Input A rising edge on this pin will enable data on the Rx pin to be loaded into the receive data register on the next eight falling edges of the data dock, TDC/RDC. RE1 and TDC/RDC should be approximately leading–edge aligned. LO1, LO2 Line Driver Outputs These outputs drive the twisted pair line with 256 kHz modified DPSK bursts each frame and are push–pull. These pins are driven to Vref when not modulating the line. MC145426 SLAVE UDLT PIN DESCRIPTIONS VDD Positive Supply Normally 5 V. VSS Negative Supply This pin is the most negative supply pin, normally 0 V. Vref Reference Output This pin is the output of the internal reference supply and should be bypassed to VDD and VSS by 0.1 µF capacitors. No external dc load should be placed on this pin. LI Line Input This input to the demodulator circuit has an internal 100 kΩ resistor tied to the internal reference node (Vref) so that an external capacitor and/or line transformer may be used to couple the signal to this part with no dc offset. LB Loopback Control When this pin is held low and PD is high (the UDLT is receiving transmissions from the master), the UDLT will use the 8 bits of demodulated PCM data in place of the 8 bits of Rx data in the return burst to the Master, thereby looping the part back on itself for system testing. SI1 and SI2 operate normally in this mode. CLK will be held low during loopback operation. VD Valid Data Output A high on this pin indicates that a valid line transmission has been demodulated. A valid transmission is determined by proper sync and the absence of detected bit errors.VD changes state on the leading edge of TE1. If no transmissions from the master have been received in the last 250 µs (derived from the internal oscillator), VD will go low without TE1 rising since TE1 is not generated in the absence of received transmissions from the master (see TE pin description for the one exception to this). MC145422•MC145426 10 SO1, SO2 Signaling Bit Outputs These outputs are received signaling bits from the master UDLT and change state on the rising edge of TE1. These outputs have standard B–series CMOS output drive capability. PD Power–Down Input/Output This is a bidirectional pin with weak output drivers such that it can be overdriven externally. When held low, the UDLT is powered down and the only active circuitry is that which is necessary for demodulation, TE1/RE1/CLK generation upon demodulation, the outputting of data received from the master, and updating of VD status. When held high, the UDLT is powered up and transmits in response to transmissions from the master. If no received bursts from the master have occurred when powered up for 250 µs (derived from the internal oscillator frequency), the UDLT will generate a free running 125 µs internal clock from the internal oscillator and will burst a transmission to the master every other internal 125 µs clock using data on the SI1 and SI2 pins and the last data word loaded into the receive register. The weak output drivers will try to force PD high when a transmission from the master is demodulated and will try to force it low if 250 µs have passed without a transmission from the master. This allows the slave UDLT to self power–up and down in demand powered loop systems. TE Tone Enable A high on this pin generates a 500 Hz square wave PCM tone and inserts it in place of the demodulated voice PCM word from the master for outputting to the Tx pin to the telset mono–circuit. A high on TE will generate TE1 and CLK from the internal oscillator when the slave is not receiving bursts from the master so that the PCM square wave can be loaded into the codec–filter. This feature allows the user to provide audio feedback for the telset keyboard depressions except during loopback. During loopback of the slave UDLT, CLK is defeated so a tone cannot be generated in this mode. TE1 Transmit Data Enable 1 Output This is a standard B–series CMOS output which goes high after the completion of demodulation of an incoming transmission from the master. It remains high for 8 CLK periods and then low until the next burst from the master is demodulated. While high, the voice data just demodulated is output on the first eight rising edges of CLK at the Tx pin. The signaling data just demodulated is output on SO1 and SO2 on TE1’s rising edge, as is VD. MOTOROLA Tx Transmit Data Output This is a standard B–series CMOS output. Voice data is output on this pin on the rising edges of CLK while TE1 is high and is high impedance when TE1 is low. X1 Crystal Input A 4.096 MHz crystal is tied between this pin and X2. A 10 MΩ resistor across X1 and X2 and 25 pF capacitors from X1 and X2 to VSS are required for stability and to ensure startup. X1 may be driven by an external CMOS clock signal if X2 is left open. X2 Crystal Output This pin is capable of driving one external CMOS input and 15 pF of additional capacitance (see X1 pin description). CLK Clock Output This is a standard B–series CMOS output which provides the data clock for the telset codec–filter. It is generated by dividing the oscillator down to 128 kHz and starts upon the completion of demodulation of an incoming burst from the master. At this time, CLK begins and TE1 goes high. CLK will remain active for 16 periods, at the end of which it will remain low until another transmission from the master is demodulated. In this manner, sync from the master is established in the slave and any clock slip between the master and the slave is absorbed each frame. CLK is generated in response to an incoming burst from the master, however, if TE is brought high, then CLK and TE1/RE1 are generated from the internal oscillator until TE is brought low or an incoming burst from the master is received. CLK is disabled when LB is held low. Rx Receive Data Input Voice data from the telset codec–filter is input on this pin on the first eight falling edges of CLK after RE1 goes high. Mu/A Tone Digital Format Input This pin determines if the PCM code of the 500 Hz square wave tone, when TE is high, is Mu–Law (Mu/A = 1) or A–Law (Mu/A = 0) format. RE1 Receive Data Enable 1 Output This is a standard B–series CMOS output which is the inverse of TE1 (see TE1 pin description). LO1, LO2 Line Driver Outputs These outputs drive the twisted pair line with 256 kHz modified DPSK bursts each frame and are push–pull. These pins are driven to Vref when the device is not modulating. MOTOROLA BACKGROUND The MC145422 master and MC145426 slave UDLT transceiver ICs main application is to bidirectionally transmit the digital signals present at a codec–filter digital–PABX backplane interface over normal telephone wire pairs. This allows the remoting of the codec–filter in a digital telephone set and enables each set to have a high speed data access to the PABX switching facility. In effect, the UDLT allows each PABX subscriber direct access to the inherent 64 kbps data routing capabilities of the PABX. The UDLT provides a means for transmitting and receiving 64 kbits of voice data and 16 kbps of signaling data in two– wire format over normal telephone pairs. The UDLT is a two– chip set consisting of a master and a slave. The master UDLT replaces the codec–filter and SLIC on the PABX line card, and transmits and receives data over the wire pair to the teleset. The UDLT appears to the linecard and backplane as if it were a PCM Codec–Filter and has almost the same digital interface features as the MC145500 series codec–filters. The slave UDLT is located in the telset and interfaces the codec–filter to the wire pair. By hooking two UDLTs back– to–back, a repeater can also be formed. The master and slave UDLTs operate in a frame synchronous manner, sync being established at the slave by the timing of the master’s transmission. The master’s sync is derived from the PABX frame sync. The UDLT operates using one twisted pair. Eight bits of voice data and two bits of signaling data are transmitted and received each frame in a half–duplex manner (i.e., the slave waits until the transmission from the master is completely received before transmitting back to the master). Transmission occurs at 256 kHz bit rate using a modified form of DPSK. This “ping– pong” mode will allow transmission of data at distances up to two kilometers before turnaround delay becomes a problem. The UDLT is so defined as to allow this data to be handled by the linecard, backplane, and PABX as if it were just another voice conversation. This allows existing PABX hardware and software to be unchanged and yet provides switched 64 kbps voice or data communications throughout its service area by simply replacing a subscriber’s linecard and teleset. A feature in the master allows one of the two signaling bits to be inserted and extracted from the backplane PCM word to allow simultaneous voice and data transmission through the PABX. Both UDLTs have a loopback feature by which the device can be tested in the user system. The slave UDLT has the additional feature of providing a 500 Hz Mu–Law or A–Law coded square wave to the codec– filter when the TE pin is brought high. This can be used to provide audio feedback in the telset during keyboard depressions. CIRCUIT DESCRIPTION GENERAL The UDLT consists of a modulator, demodulator, two intermediate data buffers, sequencing and control logic, and transmit and receive data registers. The data registers interface to the linecard or codec–filter digital interface signals, the modulator and demodulator interface the twisted pair transmission medium, while the intermediate data registers buffer data between these two sections. The UDLT is MC145422•MC145426 11 intended to operate on a single 5 V supply and can be driven by TTL or CMOS logic. MASTER OPERATION In the master, data from the linecard is loaded into the receive register each frame from the Rx pin under the control of the TDC/RDC clock and the receive data enable, RE1. RE1 controls loading of eight serial bits, henceforth referred to as the voice data word. Each MSI, these words are transferred out of the receive register to the modulation buffer for subsequent modulation onto the line. The modulation buffer takes the receive voice data word and the two signaling data input bits on SI1 and SI2 loaded on the MSI transition and formats the 10 bits into a specific order. This data field is then transmitted in a 256 kHz modified DPSK burst onto the line to the remote slave UDLT. Upon demodulating the return burst from the slave, the decoded data is transferred to the demodulation buffer and the signaling bits are stripped ready to be output on SO1 and SO2 at the next MSI. The voice data word is loaded into the transmit register as described in the TE1 pin description for outputting via the Tx pin at the TDC/RDC data clock rate under the control of TE1. VD is output on the rising edge of MSI. Timing diagrams for the master are shown in Figure 10. SLAVE OPERATION In the slave, the synchronizing event is the detection of an incoming line transmission from the master as indicated by the completion of demodulation. When an incoming burst from the master is demodulated, several events occur. As in the master, data is transferred from the demodulator to the demodulation buffer and the signaling bits are stripped for outputting at SO1 and SO2. Data in the receive register is transferred to the modulation buffer. TE1 goes high loading in data at SI1 and SI2, which will be used in the transmission burst to the master along with the data in the transmit data buffer, and outputting SO1, SO2, and VD. Modulation of the burst begins four 256 kHz periods after the completion of demodulation. While TE1 is high, voice data is output on Tx to the telset codec–filter on the rising edges of the data clock output on the CLK pin. On the ninth rising edge of CLK, TE1 goes low, RE1 goes high, and voice data from the codec–filter is input to the receiver register from the Rx pin on the next eight falling edges of CLK. RE1 is TE1 inverted and is provided to facilitate interface to the codec–filter. MC145422•MC145426 12 The CLK pin 128 kHz output is formed by dividing down the 4.096 MHz crystal frequency by 32. Slippage between the frame rate of the master (as represented by the completion of demodulation of an incoming transmission from the master) and the crystal frequency is absorbed by holding the 16th low period of CLK until the next completion of demodulation. This is shown in the slave UDLT timing diagram of Figure 11. POWER–DOWN OPERATION In the master when PD is low, the UDLT stops modulating and only that circuitry necessary to demodulate the incoming bursts and output the signaling and VD data bits is active. In this mode, if the UDLT receives a burst from the slave, the SO1, SO2, and VD pins will change state upon completion of the demodulation instead of the the rising edge of MSI. The state of these pins will not change until either three rising MSI edges have occurred without the reception of a burst from the slave or until another burst is demodulated, whichever occurs first. When PD is brought high, the master UDLT will wait either three rising MSI edges or until the MSI rising edge following the demodulation of an incoming burst before transmitting to the slave. The data for the first transmission to the slave after power–up is loaded into the UDLT during the RE1 period prior to the burst in the case of voice, and on the present rising edge of MSI for signaling data. In the slave, PD is a bidirectional pin with weak output drivers such that it can be overdriven externally. When held low, the UDLT slave is powered–down and only that circuitry necessary for demodulation, TE1/RE1/CLK generation upon demodulation, and the outputting of voice and signaling bits is active. When held high, the UDLT slave is powered–up and transmits normally in response to transmissions from the master. If no bursts have been received from the master within 250 µs after power–up (derived from the internal oscillator frequency), the UDLT generates an internal 125 µs free–running clock from the internal oscillator. The slave UDLT then bursts a transmission to the master UDLT every other 125 µs clock period using data loaded into the Rx pin during the last RE1 period and SI1, SI2 data loaded in on the internal 125 µs clock edge. The weak output drivers will try to force PD high when a transmission from the master is demodulated and will try to force it low if 250 µs have passed without a transmission from the master. This allows the slave UDLT to self power–up and down in demand power–loop systems. MOTOROLA 125 µs MSI IN ••• CCI/TDC/RDC IN TE1 IN THREE–STATE Tx OUT RE1 IN VALID DATA Rx SI1, SI2 VALID DON’T CARE •••••••••••••••••••••••••••••••••••••••••••••••••••••• DON’T CARE •••••••••••••••••••••••••••••••••••••••••••••••••••••• VALID IN •• IN SO1, SO2 OUT VD OUT DEMODULATOR SYNC OUT (INTERNAL) TRANSFER RECEIVE REGISTER TO MODULATION BUFFER, LATCH VALID DATA PIN, LATCH SI1, SI2. TWO CCI CLOCKS LATER, TRANSFER RECEIVE REGISTER TO MODULATION BUFFER, START MODULATION. TRANSFER DEMODULATOR DATA TO DEMODULATION BUFFER Figure 10. Master UDLT Timing MOTOROLA MC145422•MC145426 13 125 µs DEMODULATOR SYNC (INTERNAL) CLK (128 kHz) INTERNAL 2.048 MHz FROM XTAL • • • • • • • • •• •• •• NOTE 1 ••• ••• • • • • • • • •• •• •• • • • • • • • • • • • • ••• TE1 RE1 VOICE HIGH IMPEDANCE Tx DON’T CARE Rx SI1, SI2 VOICE DON’T CARE SO1, SO2 VD TRANSFER DEMODULATION BUFFER TO TRANSMIT REGISTER, GENERATE ENABLES, LATCH SI1, SI2, OUTPUT Tx, SO1, SO2, OUTPUT VALID DATA, START 128 kHz CLOCK, START MODULATION AFTER FOUR 256 kHz BAUD PERIODS. DEMODULATION DATA TRANSFER TO DEMODULATION BUFFER NOTE: 1. Slip between master and slave is taken up in this period. Figure 11. Slave UDLT Timing MC145422•MC145426 14 MOTOROLA Both the Differential–Phase Shift Keying and the Modified Differential–Phase–Shift Keying waveforms are shown in Figures 12 thru 14. The DPSK encodes data as phase reversals of a 256 kHz carrier. A 0 is indicated by a 180° phase shift between bit boundaries, while the signal continues in phase to indicate a 1. This method needs no additional bits to indicate the start of the burst. The modified DPSK waveform actually used in the transceivers is a slightly modified form of DPSK, as shown in Figure 12. The phase–reversal cusps of the DPSK waveform have been replaced by a 128 kHz half–cycle to lower the spectral content of the waveform, which, save for some key differences, appears quite similar to frequency shift keying. The burst always begins and ends with a half–cycle of 256 kHz, which helps locate bit boundaries. The bit pattern shown in Figure 13a shows a stable waveform due to the even number of phase changes or zeros. The waveform shown in Figure 13b shows random data patterns being modulated. Figure 14 shows the “ping–pong” signals on 3000 feet of 26 AWG twisted–pair wire as viewed at LI of the master UDLT and the slave UDLT. DIFFERENTIAL–PHASE–SHIFT KEYING MODIFIED DIFFERENTIAL–PHASE–SHIFT KEYING 1 0 1 0 1 0 1 0 0 1 Figure 12. Modified Differential Phase Shift Keying 13a. Bit Pattern — 1010101000 13b. Bit Pattern — Random Figure 13. Typical Signal Waveforms at Demodulator MOTOROLA MC145422•MC145426 15 MASTER SLAVE BIT PATTERN — 1010101000 BIT PATTERN — RANDOM Figure 14. Typical Signal Waveforms at Demodulator MC145422•MC145426 16 MOTOROLA Figure 15. Typical Multichannel Digital Line Card MOTOROLA MC145422•MC145426 17 RING TIP RING TIP N = 0.5 N = 0.5 POWER SUPPLY N = 0.5 N = 0.5 POWER SUPPLY 5.1 k N=4 110 N=2 110 5.1 k N=4 110 N=2 110 5.1 k 0.1 µF 0.1 µF 110 110 5.1 k 0.1 µF 0.1 µF 110 110 22 21 2 20 3 6 8 7 9 5 4 22 21 2 20 3 6 8 7 9 5 4 MC145422 12 V DD MSI LO1 Tx 15 Vref Rx 18 LO2 T/RDC 17 16 LI CCI 11 SI1 PD 19 SI2 RE1 14 SO1 TE1 13 SO2 SIE 10 VD SE 1 VSS LB MC145422 12 V DD MSI LO1 Tx 15 Vref Rx 18 LO2 T/RDC 17 16 LI CCI SI1 PD 11 19 SI2 RE1 14 SO1 TE1 13 SO2 SIE 10 VD SE VSS 1 LB TIMING AND CONTROL 8 kHz FRAME SYNC TRANSMIT DATA BUS RECEIVE DATA BUS 2.048 MHz DATA CLOCK TO BACKPLANE TO BACKPLANE Figure 16. Basic Digital Telset MC145422•MC145426 18 MOTOROLA XMTR 10 V 1 3 2 4 5 7 6 16 COL3 COL4 5 2 = DIGITAL GROUND = ANALOG GROUND 6 VSS 13 ROW4 14 ROW3 16 ROW1 15 ROW2 OH/T COL2 4 OSCin MS MO OSCout PULSE/TONE DIALER OPL 3 COL1 TSO DTMF OUT 100 kΩ RCE RDD 11 14 15 9 8 10 11 7 12 17 18 47 kΩ 100 kΩ 3.579545 MHz 5V TDD 10 MONOTDE 12 CIRCUIT TxI MC145503 TDC 13 RxO RDC 9 V LS Tx+ 8 VSS VAG Tx– PD Mu/A VDD S1B OPEN = ON HOOK VAG VAG S1A CLOSED = ON HOOK 1.6 kΩ 56 kΩ 10 kΩ 1 VDD RCVR 3.6 kΩ 0.1 µF 10 V +5V 0.1 µF X2 X1 SO2 SO1 TE SI2 CLK RE1 UDLT MC145426 4.7 µF SPEAKER 10 V 20 pF 1 8 10 20 21 5 2 3 4 11 22 270 Ω 1.8 k Ω LM317 VSS SI1 Mu/A LO2 LO1 VD Vref LI LB PD TE1 Rx VDD Tx 4.096 MHz 18 10 kΩ 10 V 20 pF 10 M Ω 15 9 7 12 8 17 19 18 13 14 110 Ω 110 Ω 4.7 k Ω 4.7 µF 5V 5V 5V T1 78M05 50 µF 110 Ω N=2 110 Ω N=4 4.7 k Ω 33 V 2W 20 Ω N = 0.5 N = 0.5 RING TIP MOTOROLA = DIGITAL GROUND = ANALOG GROUND +5V 1 kΩ R12 C4 10 kΩ 0.1 µF R13 VAG 6 500 Ω C12 10 µF 56 kΩ +Tx RxO RxG RxO –5V 11 VSS 7 TxI 8 –Tx 9 Mu/A 10 PDI 5 R6 R8 4 5 kΩ R7 10 kΩ 3 R5 Vref 2 VAG 1 –5V 22 RSI VDD 21 20 RDD 19 RCE 18 RDC 17 TDC 16 CCI 15 TDD 14 TDE 13 MSI VLS 12 C13 +5V 10 µF R1 10 MΩ C2 20 pF 20 pF C1 Y1 4.096 MHz 22 110Ω +5V 110Ω X2 X1 Tx TE1 TE D6 D5 VDD 17 CLK 18 Rx 19 RE1 20 LO2 21 LO1 16 15 14 13 S2 – SW112 D4 PD 5k 3 4 5 6 7 8 9 10 11 VSS R9 110Ω NC D2 C9 0.1 µF N=2 C8 5 kΩ N=4 +5V D1 R11 5 kΩ R3 1 0.1µF V ref 2 LI LB VD SI1 SO1 SI2 SO2 Mu/A D3 R10 110 Ω MC145426 MC145502 Figure 17. Full–Featured Digital Telset MC145422•MC145426 19 T1 N=1 RING TIP HOOK SWITCH S3 R2 10 kΩ +5V SPEAKER 10 kΩ 10 V PACKAGE DIMENSIONS P SUFFIX PLASTIC PACKAGE CASE 708–04 22 NOTES: 1. POSITIONAL TOLERANCE OF LEADS (D), SHALL BE WITHIN 0.25 (0.010) AT MAXIMUM MATERIAL CONDITION, IN RELATION TO SEATING PLANE AND EACH OTHER. 2. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 3. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 12 B 1 11 DIM A B C D F G H J K L M N L A N C K H G F D SEATING PLANE J M MILLIMETERS MIN MAX 27.56 28.32 8.64 9.14 3.94 5.08 0.36 0.56 1.27 1.78 2.54 BSC 1.02 1.52 0.20 0.38 2.92 3.43 10.16 BSC 15° 0° 1.02 0.51 INCHES MIN MAX 1.085 1.115 0.340 0.360 0.155 0.200 0.014 0.022 0.050 0.070 0.100 BSC 0.040 0.060 0.008 0.015 0.115 0.135 0.400 BSC 15° 0° 0.020 0.040 DW SUFFIX SOG PACKAGE CASE 751E–04 –A– 24 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN EXCESS OF D DIMENSION AT MAXIMUM MATERIAL CONDITION. 13 –B– 12X P 0.010 (0.25) 1 M B M 12 D 24X J 0.010 (0.25) M T A S B S F R C –T– SEATING PLANE M 22X K G X 45 _ DIM A B C D F G J K M P R MILLIMETERS MIN MAX 15.25 15.54 7.40 7.60 2.35 2.65 0.35 0.49 0.41 0.90 1.27 BSC 0.23 0.32 0.13 0.29 0_ 8_ 10.05 10.55 0.25 0.75 INCHES MIN MAX 0.601 0.612 0.292 0.299 0.093 0.104 0.014 0.019 0.016 0.035 0.050 BSC 0.009 0.013 0.005 0.011 0_ 8_ 0.395 0.415 0.010 0.029 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in different applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. 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Box 20912; Phoenix, Arizona 85036. 1–800–441–2447 JAPAN: Nippon Motorola Ltd.; Tatsumi–SPD–JLDC, Toshikatsu Otsuki, 6F Seibu–Butsuryu–Center, 3–14–2 Tatsumi Koto–Ku, Tokyo 135, Japan. 03–3521–8315 MFAX: [email protected] – TOUCHTONE (602) 244–6609 INTERNET: http://Design–NET.com HONG KONG: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298 MC145422•MC145426 20 ◊ *MC145422/D* MC145422/D MOTOROLA